• Sebastian Siewior's avatar
    spi: fix the read path in spidev · 4b1295b0
    Sebastian Siewior authored
    This got broken by the recent "fix rmmod $spi_driver while spidev-user is
    active".  I tested the rmmod & write path but didn't check the read path.
    I am sorry.  The read logic changed and spidev_sync_read() +
    spidev_sync_write() do not return zero on success anymore but the number
    of bytes that has been transfered over the bus.  This patch changes the
    logic and copy_to_user() gets called again.
    
    The write path returns the number of bytes which are written to the
    underlying device what may be less than the requested size.  This patch
    makes the same change to the read path or else we request a read of 20
    bytes, get 10, don't call copy to user and report to the user that we read
    10 bytes.
    
    [akpm@linux-foundation.org: remove test of known-to-be-zero local]
    Signed-off-by: default avatarSebastian Siewior <bigeasy@linutronix.de>
    Acked-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    4b1295b0
spidev.c 16.5 KB